Refrigerating apparatus



H. J. TENNISWOOD ETAL 3,308,635

March 14, 1967 REFRI GERATING APPARATUS Filed May 5, 1965 3 Sheets-Sheet1 INVENTORSY HOWARD J. TENNISWOOD LEO PETERS B -flmgm OLWm March 1967 H.J. TENNISWOOD QETAYL 3,308,635

REFRIGERATING APPARATUS Filed May 1965 3 Sheets-Sheet 2 Fl 4 I Q |O-r 37I 50 1 5 so 22 INVENTORS: I HOWARD J. TENNISWOOD LEO PETERS ATT'YS March1967 H. J. TENNISWOOD \ETAL\ 3,308,635

REFRIGERAT ING APPARATUS Filed May 5, 1965 3 Shets-Sheet 3 FIGIZINVENTORSI HOWARD J. TENNISWOOD LEO PETERS ATTYS L i I U I J 58 UnitedStates Patent 3,308,635 REFREGERATIN G APPARATUS Howard J. Tenniswood,212 Richards St., Adrian, Mich. 49221, and Leo Peters, 750 PlymouthRoad, SE, Grand Rapids, Mich. 495% Filed May 3, 1965, Ser. No. 452,629 8(Iiainrs. (Cl. 62-277) This invention relates to a refrigeratingapparatus, and, more particularly, to an electrically energized,mechanically operated, portable refrigerated plate for holding butterpatties in restaurants and cafeterias in cold, easyto-dispensecondition.

This invention is useful in connection with the refrigeration of allbutter patties, but is particularly advantageous for decorative-surfacedpatties, such as those having imprinted or embossed designs.Decorative-surfaced butter makes up about 70% of all butter pattiesserved in eating establishments in the United States. It is this segmentof the industry that this invention can serve especially advantageously.

All butter requires refrigeration to prevent the damaging effects causedby softening and melting at normal room temperatures, butdecorative-surfaced butter is particularly subject to damage if allowedto touch anything while in a warm condition. All restaurants desire tohold and dispense their surface decorated patties in a manner thateliminates surface damage. But under past methods for holding anddispensing butter patties, this has not been generally possible. Butterpatties with designs on their to surfaces, especially embossed(upraised) surfaces, must be kept cold, upright, out of contact with,and away from pressures exerted by another surface. This inventionenables these basic requirements to be met in a highly practical,commercially-acceptable manner. In particular, the invention fulfillsthe need providing refrigcrating apparatus for butter patties adaptedfor use on service islands.

Restaurants and dining rooms that have table service also have serviceislands near diners tables. In these islands, waitresses can give rapidservice for frequently served staple foods. Such foods always includecoffee and butter. Coffee is kept hot by and is dispensed from modern,electrically operated, portable hotplates. Butter by contrast isnormally kept cold by and dispensed out of manually-maintained beds ofcrushed ice or ice water held in bowls or old-fashioned crocks, a methodwhich damages butter. There has been no commercially-practical means forrefrigerating surface-decorated butter patties in an efficient, lowcost, easy to use and easy to move manner. No modern efficient equipmentcomparable to that used for hot foods and cold beverages is availablefor butter. That 70% segment of the butter patties served inrestaurants, referred to above, still is held in crushed ice or icewater and is dispensed by jabbing with a fork. This practice is highlyunsatisfactory: butter becomes crushed and mutilated, bleached by directice contact, speckled with drops of water, and involves waste of butterand time involved in daily preparation, maintenance and cleanup.Further, when butter is held in ice, it becomes too cold and hard forspreading. Such butter breaks bread and at best can only be lumped on-itleaves some areas of bread or rolls heavily covered with butter andother areas completely devoid of it.

It is an object of this invention to provide a solution for theabove-mentioned problem. More specifically, it is an object of thisinvention to provide a means for holding butter patties on restaurantservice islands in a cold, quality-preserving, firm-bodied butspreadable condition, without damaging weights or pressures on them,without the need for daily preparation and cleanup and in a quicklyaccessible, easy to dispense condition.

Another object is to provide a means for maintaining a steady,concentrated, relatively invariable temperature slightly above freezingfor refrigerating butter patties which are held on and are readilyaccessible for serving from an open area located in a room characterizedby a substantially higher ambient temperature.

Still another object of the invention is to provide a refrigeratingapparatus, especially suited for the maintenance and reducedtemperatures of butter patties in which the deteriorating and unsanitarypresence of water condensation is avoided.

Other objects and advantages of the invention may be seen in the detailsof operation and construction set down in this specification.

The invention is explained in conjunction with an illustrativeembodiment in the accompanying drawings, in which- FIG. 1 is aperspective view of an embodiment of the invention equipped with asanitary cover and also arranged to support serving plates;

FIG. 2 is a perspective exploded view of the apparatus seen in FIG. 1;

FIG. 3 is an enlarged fragmentary perspective view of the refrigerationplate portion of the apparatus seen in F168. 1 and 2;

FIG. 4 is a longitudinal sectional view such as would be seen along thesight line 4-4 applied to FIG. 3;

FIG. 5 is a transverse sectonal view such as would be seen along thesight line 5-5 applied to FIG. 3;

FIG. 6 is a schematic piping diagram of the refrigeration circuitutilized in connection with the apparatus seen in the preceding view;

FIG. 7 is a top plan view of the apparatus of FIG. 1, but without thesanitary cover and serving plates;

FIG. 8 is a bottom view of the structure of FIG. 7;

FIG. 9 is a rear elevational view of the apparatus of FIG. 7;

FIG. 10 is a side elevational view of the apparatus of FIG. 7;

FIG. 11 is a front elevational view of the apparatus of FIG. 7; and

FIG. 12 is an enlarged fragmentary sectional view of the lower righthandportion of FIG. 4 showing the details of construction of the condensateevaporating tray and compressor support.

In the illustration given and with particular reference to FIG. 1, thenumeral 10 designates generally the refrigerating apparatus constructedaccording to the teachings of this invention. The apparatus 10 includesa generally rectangular enclosure 11 providing an upper cooling surfaceas at 12 (see, particularly, FIGS. 2 and 3). At the rear of theapparatus a higher enclosure generally designated 13 provides a housingfor the means for refrigerating the surface 12.

In FIG. 1, a side portion of the upper cooled surface is used as astorage facility for a stack of serving plates 14 with individual platesbeing designated 15 and carrying thereon decorative-surface butterpatties 16. At the left in FIGS. 1 and 2, a protective or sanitarysub-assembly generally designated 17 is provided to confine and protectbutter patties between periods of peak usage. The details of thesub-assembly 17 will be described in greater detail hereinafter and itwill be appreciated that the use of this sub-assembly is optional.

The refrigerating portion of the apparatus 10 can be more readilyappreciated from a consideration of FIGS. 4 and 5 which are longitudinaland transverse sections, respectively, of the apparatus as seen in FIG.3. Referring now to FIG. 4, it will be seen that the surface 12 isprovided by a relatively thin metal plate supported atop a generallyrectangular frame generally designated 18. The frame 18 is defined by abottom plate or pan 19 which is slightly longer than the plate 12 andwhich provides an upstanding rear wall as at 20- integral with thebottom plate or wall 19. Further, the rear wall 20 is inwardly turned atits top edge in order to provide a supporting flange 21. The remainderof the generally rectangular frame 18 is provided by a C-shaped wrapperor channel portion 22. The wrapper portion 22 can also be seen in FIG. 3and is seen to provide the two side walls of the bottom portion of theapparatus 10 as well as the front wall (see also FIG. 11). The channelshape of the wrapper 22 permits a weldable connection between it and thebottom wall 19 so as to develop the rectangular frame 18.

The refrigerating surface 12 is provided as part of an evaporator unitgenerally designated 23 (see FIGS. 4 and 5). The unit 23 includes abottom wall or panshaped element 24. Along its four sides, the pan 24 isequipped with L-shaped flanges as at 25 over which the plate 12 iscrimped. The flanges 25 are supported on the inwardly extending, flanges26 of the wrapper 22 and the upper flange 21 of the bottom wall 19.Serving to thermally insulate the unit 23 from the rectangular frame 18is flexible urethane tape as at 27 (see FIG. 5) and a silicone sealingcompound 28. The sealing compound 28 extends perimetrically around theflange 25 to reduce conductive thermal transmission. Additionally, theflange 26 along one side and along one end as at 29 and 30 (see FIG. 3)are equipped with a ridge element for the purpose of confining andpositioning the sub-assembly 17 and for limiting the possible outflow ofcondensate developed on the cooling surf-ace 12.

The condensate developed on the cooling surface 12 is advantageouslyremoved through a depression or drain trough 31 (see particularly FIGS.3 and 5). The trough 31 is integrally formed in the surface 12 and iscoupled to a condensate tray 32 (see FIGS. 3 and 4) by means of adrainage tube 33.

The evaporator unit 23 further includes a serpentine arrangement ofevaporator coils 34 (see FIGS. 4 and 6) which are embedded in athermally conducting mastic material 35 filling the space between theplate 12 and the pan 24. Additionally, mounted within the evaporatorunit 23 is a tube into which is placed a thermostatic bulb as at 36 (seeFIGS. 3 and 6). The thermostatic bulb is coupled to the usual compressorswitch 37a interposed in the voltage supply line to the compressor 37(see FIG. 4) for the purpose of energizing and de-energizing the same ascooling requirements are changed.

The evaporator unit 23 is advantageously thermally insulated along thelower side and further optimally supported by means of a rigid urethanefoam as at 38 (see FIGS. 4 and 5). For the purpose of filling the spacebetween the bottom wall 19 of the frame 18 and the evaporator unit 23,the bottom wall 19 is equipped with an access opening as at 39 (FIG. 8)which is closed by a formed plastic cap. In the course of manufacture,liquidfoamed urethane plastic is caused to flow through the opening 39into the space between the pans 24 and 19, and after the same hassolidified, remains in place and is further preserved againstcontamination by means of the cap closing the opening 39.

Referring now to FIGS. 4 and 6, it will be seen that the compressor 37is equipped with a hot. gas outlet line as at 40 which has a firstportion arranged in serpentine fashion as at 41 under the condensatetray 32. Thus, the hottest refrigerant is lit thermally conductingrelation with the condensate tray 32. Thus, the hottest refrigerant isin thermally conducting relation with the condensate liquid emanatingfrom the cold surface 12. In FIG. 12, it will be seen that theserpentine tubes 4141 are bonded to the underside of the bottom 42 ofthe tray 32 as at 4112.

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Referring again to FIG. 6, it will be seen that the hot line includes asa second and continuing portion 43, a tube which extends perimetricallyaround the frame 18 as at 43a (see FIG. 4), 4312 (see FIGS), 43c (seeFIG. 4) and 43d (see FIG. 5). The portions 43a43d are bonded to thebottom wall 19 and the wrapper 22 in thermallyconducting relation bymeans of thermomastic material such as that employed at 35 relative tothe evaporator unit 23. This warms the wrapper 22 and wall 20, which isin close contact at a point with plate 12, and prevents condensationfrom forming on wrapper 22 and wall 20 by virtue of the transfer of heatfrom the hot line portions 43a-43d to the wrapper 22.

Ultimately, the hot line 43d (see FIG. 6) is coupled to the upperportion of a condenser generally designated 44 and which is seen inFIGS. 6 and 9.

Further tracing the refrigerant line in FIG. 6, it will be seen that theoutlet of the condenser leads to a dryer and strainer unit 45 and thenleads to the evaporator tubes 34 through a restrictor tube or capillaryline 46. The evaporator tubes 34 at their outlet are coupled to a returncold line 47 which is arranged in thermally conductive relation to therestriction tube 46 (as by bonding at 46:: in FIG. 6), and ultimatelythe return line 47 leads to the suction inlet 48 of the compressor.

The compressor 37 is housed within an enclosure generally designated 49(see FIG. 4) and the enclosure 49 is developed by an upstanding frontwall 50 of general channel shape and which is seeen to be secured as at51 to the flange 21. The enclosure is completed by side walls 52 and atop wall 53 (see FIGS. 10 and 7), respectively. Each of the walls issuitably insulated as at 54 (see FIG. 4) and the top wall 53 adjacentthe open back 55 is equipped with a vent 56 permitting the advantageousoutflow of air heated by contact with the compressor and which alsocarries out the evaporated moisture from the condensate tray 32. i

As seen in FIGS .4 and 9, theconde-nser 44 is positioned in the openback 49 for contact with the air. We find it advantageous to providebumpers as at 57 (FIGS. 7 and 9) to insure spacing the condenser 44 fromany vertical wall. Feet 58 (see FIGS. 4 and 8) are provided on thewrapper 22 to space the apparatus above any supporting surface, and inthis connection it will be noted that the serpentine coil arrangement 41under the condensate tray 32 is also open to the atmosphere. Referenceto FIG. 12 reveals that the condensate tray is upset as at 59 so as toprovide supports forthe compressor 37. The compressor base flanges 44aare positioned within a rubber grommet 6%) which in turn is secured tothe raised portion 59 by means of a stud 61 riveted at its lower portionas at 61a. A hairpin clip 62 in combination with a metal washer 63insures stable positioning of the compressor base 44a. Thus, thecondensate tray 32 is immobilized as part of the compressor, yet thesupport of the compressor (through openings as at 64 in the tray 32)does not permit gravity outflow of any liquid condensate-this beingprevented by the grommet 60. The condensate tray 32 is additionallyintegrated with the frame 18 by means of transversely extending anglesas at 65 extending between the sides of the wrap per 22.

As a specific example of the invention, the apparatus 10 has a width of18" as viewed from the frontsee FIG. ll-a height of the surface 12 of 2/2", a length of 24" as viewed in FIG. 10. and a height of thecompressor enclosure of 8 /2". The evaporator unit 23 is constructedwith 20 gauge stainless steel providing the upper plate 12 and 24 gaugeZinc-coated steel providing the pan 24. The zinc-coated steel isslightly rough in its surface configuration to provide a good anchoragefor the urethane foam. The urethane foam has a thickness of about 1%",while the evaporator unit 23 has a thickness of about inside dimensionbetween the plate 12 and the pan 24. The filling of mastic material hasa specific gravity of approximately 1.5, and this is found advantag'eousin working as a heat sink surrounding the evaporator coils 34. Therefrigerant is No. 12, a dichlorodifiuoromethane operating atapproximately 135 psi. head and approximately p.s.i. evaporatingpressure. The overall weight of the exemplary unit is lbs., which makesfor advantageous portability.

The additional parts indicated to make up the subassembly 17 include aperimetric frame portion 66 which supports transparent removable coversas at 67.

In the operation of the invention, a horizontally positionedrefrigerator plate is utilized on which the butter rests in pressure-dcontact due to the weight of the butter itself. Refrigeration isprovided for the butter through conduction of heat-as contrasted toconvection, and cooling is maintained by the cooperating pressure fromthe butter itself, not by air stratification or convection. Heat istransferred out of the butter and into the refrigeration system withoutmovement of either the butter or any refrigerated air.

The construction described is particularly advantageous in operationthrough utilization of the heat sink principle. The evaporator unit 23,upon being initially subjected to refrigeration, develops a coolingpattern corre sponding to the serpentine pattern of the coils 3-4therein. However, within minutes the surface temperature on the platebecomes uniform and the serpentine pattern of cooling is erased. Thus, auniform cooling surface is provide-d and this stems from the relativelythin sandwich construction of the evaporator unit 23. The masticmaterial, coupled with the metal plate and pan and the insulatingsupport provided thereto by the urethane material 38, makes possible theelimination of the usual type of air sensing temperature control. Thisfurther eliminates the undesirable rapid cycling of the refrigerationunit. With the heat sink principle provided in the invention, the undesirable cycling is avoided.

The coaction of the urethane 27 and silicone cement 23 material with theevaporator unit 23 is advantageous in preventing the flow of heat inwardfrom the perimetric walls of the frame 10. In this respect, it differsfrom the conventional thermal break used in refrigerators. The urethanematerial constituting the thermal break also seals off the unit fromundesirable condensation.

Further in the operation, the air circulating in and about the rear endof the unit follows a chimney pattern in exhausting through the vent 56.This air creates a slight indraft in and around the condenser 44 anddoes not impair the operation of the condenser by having to flow out ofthe rear of the condenser enclosure 13. Further, the location of theenclosure 13 essentially above the evaporator unit 23 and by providingdischarge of air in an upward pattern, prevents unfavorable heattransfer from the mechanical side of the system to the refrigerationside.

The inventive construction provides a continuous and automatic operationwithout failure over a long life. In

achieving this, the operation is fast and uniform in absorbing the heatextracted from the butter when required, but at the same time uniformlyreleases the heat to the evaporator. Further, the unit is adapted toserve the temperature requirements of the butter alone. Butter inrestauranhcafeteria use requires a refrigerating temperature whichideally is peculiar to it alone. The temperature is about 40 F. or morebroadly in the 3545 F. range. At this temperature, butter issufficiently cold to maintain fresh quality, sufiiciently hard tomaintain shape and make dispensing easy, yet sufficiently warm to enableit to come to the ideal soft-spreading temperature of F. when exposed to70 F. room temperature during the four to eight minute interval betweenthe time of dispensing and the time of spreading by a restaurant patron.

The unit is further advantageous in holding the butter in an open,easily accessible, removable-without-damage,

quickly dispensable and sanitary condition. In particular, the buttercan be readily removed by utilizing the available restaurant implements,such as forks and knives, to slip the same under a patty to lift anddispense it. It is not necessary to jab, spear or engage in amultilating action in order to grasp and hold a butter patty. Besidesproviding the advantageous accessibility, the instant invention providesa refrigeration apparatus which is economical to operate, involving aminimum of waste. The butter is provided on a flat exposed surface whichcan be easily shielded from air currents if desired, but even in theabsence of such shielding, the film of colder air surrounding the uniteffectively minimizes heat transfer. This is further implemented throughthe enclosure configuration 13 utilized for the heat generating portionsof the apparatus, as pointed out previously.

Further, in operation the unit automatically controls the amount anddisposal of water condensate on the outside (topside) of the plate 12.The inside (underside) is sealed, therefore, and this is advantageous inpreventing mold growth, rust and corrosion, maintaining good sanitationin unseen areas, and eliminating the unwanted increase in heatabsorption by exposure of both sides of the refrigerator evaporatingcoil.

While in the foregoing specification, a detailed description of anembodiment of the invention has been set down for the purpose ofillustration, many variations in the details herein given may be made bythose skilled in the art without departing from the spirit and scope ofthe invention.

We claim:

1. Refrigerating apparatus comprising a generally rectangular frame, ametal evaporator plate mounted on said frame and providing a generallyhorizontal exposed upper surface, an evaporator coil mounted in saidframe below said plate, a heat conductive material surrounding said coiland contacting the under surface of said plate, a heat insulatingmaterial below said heat conductive material and providing a support forsaid plate within said frame, a compressor compartment in said frameadjacent one edge of said plate and equipped with a compressoroperatively coupled to said coil, and drain means in said plateconnected to said compartment, said compartment including an enclosureprovided as part of said frame, said enclosure projecting verticallyabove said plate, said enclosure having a pair of vertically extendingsides arranged generally parallel to said edge and the enclosure sideremote from said plate edge being open and having a condenser coilpositioned therein, said condenser coil projecting above said plate.

2. The structure of claim 1 in which said enclosure is equipped with apan arranged to receive condensate from said drain means, saidcompressor being equipped with an outlet line arranged below said panand in heat transfer relation therewith.

3. The structure of claim 1 in which said compressor is equipped wit-han outlet line disposed perimetrically relative to said frame andseparated from said plate by said heat insulating material.

4. The structure of claim 1 in which said enclosure is equipped with atopwall, and an exhaust aperture in said topwall adjacent said remoteside.

5. Refrigerating apparatus comprising a generally rectangular open topframe defining side, bottom and end walls, said sidewalls being extendedat one end to provide a base for a compressor enclosure, an evaporatorunit supported in said frame closing the open top thereof, said unitincluding a generally horizontal metal top plate of relatively highthermal conductivity, a pan perimetrically secured to said plate andspaced therebelow, refrigerant evaporator coils arranged in serpentinefashion between said plate and pan, and a thermally conductive masticmaterial filling the space between said pan and plate and surroundingsaid coils, a relatively rigid thermal insulation material filling saidframe in supporting relation with said unit, a thermally insulating sealbetween said plate and adjacent portions of said frame, said plateadjacent one side being equipped with a trough-like depression extendingsubstantially between the frame ends, said enclosure including avertical wall extending the said frame one end wall and said extendedside walls, said enclosure further including a top wall and definingthereby an open back, an aperture in said top wall adjacent said openback, a condensate pan in said enclosure adjacent the bottom thereof, adrain connection connecting said depression and condensate pan, acompressor mounted in said enclosure and equipped with inlet and outletconnections, a hot refrigerant line coupled to said outlet and having afirst portion disposed in serpentine fashion below said condensate panand secured thereto, said line having a second portion extendinggenerally perimetrically interiorly of said frame and bonded withthermally conductive material to said frame adjacent the bottom wallthereof, a condenser coil in said enclosure open back, said line secondportion being connected to said condenser coil, a cold line connected tosaid compressor inlet and coupled to one end of said evaporator coil,the other end of said evaporator coil being coupled to said condensercoil, a thermostat embedded in said mastic material, and aswitch-equipped source of operably associated with said compressorthermostat.

6. The structure of claim 5 in which said thermal insulating material isa urethane, said pan being constructed of metal and surface bonded tosaid urethane material.

7. Refrigerating apparatus comprising a generally rectangular frame, ametal evaporator plate mounted on said frame and providing a generallyhorizontal exposed upper surface, an evaporator coil mounted in saidframe below said plate, a heat conductive material surrounding said coiland contacting the under surface of said plate, a heat insulatingmaterial below said heat conductive material and providing a support forsaid plate within said frame, a compressor compartment in said frameadjacent one edge of said plate and equipped with a compressoroperatively coupled to said coil, and drain means in said plateconnected to said compartment, said drain means including an elongatedtrough extending generally perpendicularly to said one edge and adjacentto another edge of said plate, two other edges of said plate beingequipped with upstanding walls, and a subframe removably positionedwithin said walls for hygienically confirning butter patties on saidplate.

8. Refrigerating apparatus comprising a generally rectangular frame, ametal evaporator plate mounted on said frame and providing a generallyhorizontal exposed upper surface, an evaporator coil mounted in saidframe below said plate, a heat conductive material surrounding said coiland contacting the under surface of said plate, said conductive materialbeing confined within a generally rectangular pan, said plateconstituting a cover for said pan, and insulating cement and tapebetween said plate and adjacent portions of said frame, a heatinsulating material below said heat conductive material and-providing asupport for said plate within said frame, a compressor compartment insaid frame adjacent one edge of said plate and equipped with acompressor operatively coupled to said coil, and drain means in saidplate connected to said compartment.

References (Iited by the Examiner UNITED STATES PATENTS 1,955,186 4/1934Hill 62-458 1,993,328 3/1935 Ingvardsen 62458 2,124,110 7/1938 Hall62-458 2,175,946 10/1939 Smith 62-279 2,640,329 6/1953 Ingvardsen 624582,759,339 8/1956 Kundert 62-458 WILLIAM J. WYE, Primary Examiner.

1. REFRIGERATING APPARATUS COMPRISING A GENERALLY RECTANGULAR FRAME, AMETAL EVAPORATOR PLATE MOUNTED ON SAID FRAME AND PROVIDING A GENERALLYHORIZONTAL EXPOSED UPPER SURFACE, AN EVAPORATOR COIL MOUNTED IN SAIDFRAME BELOW SAID PLATE, A HEAT CONDUCTIVE MATERIAL SURROUNDING SAID COILAND CONTACTING THE UNDER SURFACE OF SAID PLATE, A HEAT INSULATINGMATERIAL BELOW SAID HEAT CONDUCTIVE MATERIAL AND PROVIDING A SUPPORT FORSAID PLATE WITHIN SAID FRAME, A COMPRESSOR COMPARTMENT IN SAID FRAMEADJACENT ONE EDGE OF SAID PLATE AND EQUIPPED WITH A COMPRESSOROPERATIVELY COUPLED TO SAID COIL, AND DRAIN MEANS IN SAID PLATECONNECTED TO SAID COMPARTMENT IN SAID FRAME ADPARTMENT INCLUDING ANENCLOSURE PROVIDED AS PART OF SAID FRAME, SAID ENCLOSURE PROJECTINGVERTICALLY ABOVE SAID PLATE, SAID ENCLOSURE HAVING A PAIR OF VERTICALLYEXTENDING SIDES ARRANGED GENERALLY PARALLEL TO SAID EDGE AND THEENCLOSURE SIDE REMOTE FROM SAID PLATE EDGE BEING OPEN AND HAVING ACONDENSER COIL POSITIONED THEREIN, SAID CONDENSER COIL PROJECTING ABOVESAID PLATE.